Small irregular shaped chunk of Vaseline glass about 0.5" diameter or larger comes with a 5mm UV LED and a CR2032 coin battery. Just place the UV LED leads across the battery (observing polarity) and you will see a brilliant yellow/green glow from the glass chunk. The Vaseline glass chunk is slightly radioactive and will cause very sensitive Geiger counters to click. Note: Glass chunk will vary from picture.
